Lawn Disease and Fungus

Lawn or grass diseases are very common and can be caused by a variety of factors. Unfortunately, lawn diseases can sometimes be hard to diagnose and treat. Here are a few common lawn diseases and their symptoms:


Lawns that have reddish brown spots with yellow markings may have been affected by anthracnose. Spots may be anywhere from 2 inches to 20 feet in diameter. Anthracnose is a lawn disease that is commonly caused by wet or humid weather. A fungicide can be used to repair the lawn.

Brown Patches:

This grass and lawn disease is extremely common in hot weather and causes circular brown patches to appear on the lawn. Spots may be anywhere from several inches to several feet in diameter. Lawns with brown patches should be thatched, aerated, watered and sprinkled with compost.

Dollar Spot:

A dollar spot outbreak may occur during summer when the benefits of fall-applied nitrogen have been expended and turf is growing slowly. Disease will be suppressed with supplemental fertilizer applications in midsummer. Regular mowing to a height of 2-3 inches will hasten turf recovery. A fungicide may be applied by a professional lawn service.

Fairy Rings:

A Fairy Ring is a lawn disease that is caused by certain types of fungus. The effect and appearance of a fairy ring can vary depending on what type of fungus is causing the problem but they generally form one or more of the following: a ring of mushrooms on the lawn where there is sufficient moisture or a ring of deep green or lush looking grass with yellowed grass inside the circle.

Fusarium Blight:

Lawns that have donut or crescent shaped patches of dead or dying (reddish-brown) grass may be afflicted with fusarium blight. Fusarium blight is very similar to other common lawn diseases, but can be hard to diagnose and control. Lawns should be thatched and aerated. Mowing should be kept to a bare minimum, as the grass will be better off if left high.

Gray Snow Mold:

Gray snow mold is first noticeable in early spring, after the snow melts. It usually shows up in areas where snow has accumulated for long periods of time i.e. along driveways and in areas where snow drifts develop. Grass that has been affected by gray snow mold has a matted, bleached, gray look to it. In most cases, infected grass blades are killed, but crowns and roots usually survive. An aeration and over seeding may be necessary if infected areas do not recover.

Powdery Mildew:

This is usually caused by poor air circulation, high humidity, and dense shade, powdery mildew is a fungus that attacks grass blades and leaves. The fungus consists of a white powdery substance and will kill the grass if left unchecked. This lawn disease can be treated with fungicide.


This lawn disease commonly occurs in hot weather and causes a reddish-orange powder to appear on the grass. Severe rust will cause the grass to turn yellow and die. With adequate mowing, fertilization, and irrigation, this lawn disease can be easily controlled.

Need Help? Contact Us!

If you have any questions about a potential disease on your lawn, please call Green      at 630-231-0007 for help. We have experienced lawn care professionals that can alleviate any issue you may be experiencing.

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